Closure for knock-out holes



June a, 1937. M. 'cox- 2, 8

I CLOSURE FOR KNOCK-OUT HOLES Fil ed April 20, 1936 IFIQ: l. Fimi;

)wvslvror "LER Y Cox, 23%

Patented June 8, 1937 UNITED STATES PATENT OFFICE 2,083,056 CLOSURE FOR KNOCK-OUT HOLES Leroy M. Cox, Anaheim, Calif. Application April 20, 1938, Serial No. 75,387

2 Claims.

This invention relates to devices used for closing holes in electric connection boxes that are customarily provided with so-called knock-outs and similar devices where a closing of holes can be accomplished in a similar manner.

One of the objects of this invention is to provide a cheap, reliable and durable closing device that may be quickly inserted or removed and stillbe substantially secure when in place.

Another object is to provide. a device that may be quickly inserted or removed without the use of any tools where the application of tools might cause damage or at places that make the use of tools difficult.

Another object is to provide a device that can be applied from one side where the other side is inaccessible.

Another object is to provide a device that may be inserted or removed repeatedly without damage to the device itself or to parts to which it is applied.

Another object is to provide a distinctly sub-- stantial device so designed and constructed that a loosing of parts becomes negligible if not impossible. I

Another object is to provide a device-that may be made of any required strength, thickness, or type of material, as against fire protection, and still embody the desired resiliency for ready insertion or removal.

Another object is to provide a device with retaining means suitable for a firm and constant engagement, tight and rattle-proof, while in place.

Other objects will appear from the following description and appended claims as well as from the accompanying drawing, in which Fig. 1 is a general mid-sectional view ofv one simple form of the device according to this invention. i

Fig. 2 is a general mid-sectional view of a socalled knock-out.

Fig. 3 is a plan view as seen in the direction of the arrowiinFlg. 1.

Fig. 4 is a plan view or a so-called-knock-out.

Fig. 5 is an edge view of a device of the form illustrated in Fig. 1, as it appears when partly removed or inserted.

Fig. 6 is an edge view of a slightly modified device as it appears when partly removed or inserted.

Fig. 7 is a plan view or the modified device as seeninthedirectionotthearmwl mm. 5.

Fig.8isaplanviewofaknock-outotasiightly I modified form.

(Cl. 24'I-26) Fig. 9 is a plan view of a knock-out of another slightly modified form of knock-out.

Electric connection or fuse boxes are customarily provided with so-c'alled knock-outs of a type similar to the illustrations in Figs. 2 and 4, an electrician merely knocking outany number of such knock-outs required for the insertion of wires or other appliances.

Frequently, moreover, it becomes necessary to close a hole from which such a knock-out has been removed.

Such a closing, of course, must be done with due regard for safety and appearance.

Though I am aware that various devices for this purpose can be had on the open market, generally, however, I experienced unsatisfactory conditions, such as rattling, difficult to be inserted, difiicult to remove, not tight, difficulty when only to be reached from one side, and many otherdisagreeable features, perhaps, not necessarily recited here.

The simple device illustrated in Figs. 1 and 3 is merely provided with a spring-like member l0, which may be secured in any suitable known or required manner, though a rivet has been indicated at I I, but it will readily be understood that spot-welding, soldering, or other means might be just as expedient, depending really largely on the material of the closure l2 itself, which, in turn,

might be of various materials, depending largely on the use or requirements in different instances. When the closure is made of sheet material it is preferably stamped as shown to form a shoulder edge l3, indicated in Fig. 3, to become snugly recess its outside as in a stamping, such as such as bakelite, of course, it is not necessary to shown in Figs. 1, 3, 5, 6, or '7, and from this it should be understood that if made of other materlal it does not have to have a stamped appearance, though the shouldered edge I3 is of a preierred form, for the purpose desired here, as set forth above. 1

For -inserting or removing this simple device of Figs. 1 and 3, one spring-end is simply-shifted over the materiality as indicated at lhuntil the'opposite spring-end becomes free as indicated at I, when this device may easily be either removed or fully inserted. I

To fully insert this device it is merely shifted in the opposite direction so that the spring-end .lh, will engage in a similar manner as springend Illa until the shoulder l3 becomes seated against the edge H of the material is in the manner illustrated in Fig. 1.

When a removal is desired the device is simply tilted outwardly until the spring-end l points above or in front of the material l5 when the whole device may readily be withdrawn from the material i 5, since the spring-end Ills is merely slightly frictionally engaging over the inside of the material I5 in the illustration of Fig. 5.

The slightly modified form illustrated in Figs. 6 and 7 difiers only in having about half of the spring member ID of the device of Figs. 1, 3, and 5, the spring member I00 serving otherwise in a similar manner for removal and insertions, the engagement at the opposite side being completed by the lug l6, suitably depressed from the closure I28, there being otherwise the same shoulder I3 to engage with the edge M.

The illustrations of Figs. 8 and 9 merely show different shapes of knock-outs to malge it clear that the shape of closures must be according to any requirement, and, as already stated, a closure may be made to suit requirements for other than in electric connection and fuse boxes and for any such other requirements the closure and its parts must, of course, be designed to make this invention applicable.

Having thus described my invention, I claim:---

1. In a device of the class described, in combination with a wall having an opening, a closing member comprising a first portion of larger dimensions than the opening engaging one surface of the wall adjacent the opening, a raised second portion of substantially lesser dimensions than the opening, integral with the first portion and for insertion within the opening, resilient radial means attached to the second portion and engaging the other surface of the wall adjacent the opening.

2. In a device of the class described, in combination with a wall having an opening with an edge surrounded by inner and outer surfaces of the wall, a closing member comprising a first portion of larger dimensions than the opening to engage one surface, a raised second portion integral with the first portion and of substantially lesser dimensions than the opening, and resilient means attached to the second portion at a point away from the edge inwardly and with its free termination extending beyond the contours of the opening outwardly to engage with the other surface.

' LEROY M. COX. 

